Study visits will occur monthly for the first year, then every 3 months thereafter for the remainder of the study. Blood and urine collection will occur at every visit. A physical exam and medical and medication history will occur every 3 months; also, participants will be asked to complete several questionnaires to assess disease activity, health status, and tobacco, alcohol, and drug use. Participants may have additional study visits if a disease flare or disease-related complications occur during the study.